Dental engine



(No Model.) 3Sheets-Shet 1.

J. S. CAMPBELL.

DENTAL ENGINE.

No. 461,146. Patented Oct. 13,1891.

WITNES S E 51 (No Model) 3 Sheets-Sheet 2.

J. S. CAMPBELL.

DENTAL ENGINE.

No. 461,146. Patented Oct; 18,1891.

kw/$0 X A l WITNESSES? tages of construction, as hereinafter set forth.

fication.

UNITED STATES PATENT OFFICE.

JOHN SHALLEY CAMPBELL, OF LONDON, ENGLAND, ASSIGNOR TO THE CAR- ROLL ALUMINUM MANUFACTURING COMPANY AND EDWVARD A. PEIROE, OF NE\V YORK, AND J. OTIS COX, OF BROOKLYN, NEYV YORK.

DENTAL ENGINE.

SPECIFICATION forming part of Letters Patent No. 461,146, dated October 13, 1891.

Application filed December 2, 1889; Serial No. 332,174. (No model.)

To all whom it may concern.-

Be it-known that 1, JOHN SMALLEY CAMP- BELL, dentist, a citizen of the United States, and a resident at present of London, in the county of Middlesex, England, have invented certain new and useful Improvements in Dental Engines, of which the following is aspeci- This invention relates to dental engines of the type designed to be operated by the foot of the dentist, such an engine comprising a base which supports the tool-carrying standard, a main driving-wheel, and a treadle with necessary accessories for communicating the motion of the treadle to the main drivingwheel and fortransmitting the power of said wheel to the drill or other tool carried by the standard.

The object of the present invention is to combine a dental engine embodying the characteristics above mentioned, and so arranged as to be capable of having its several parts folded together with a dental chair in such manner as that the engine will constitute a part of the operating-chair and will be concealed beneath the chair from the view of the patient, and will be capable of being revolved around the base of the chair when hein g used. I

A further object is to produce a horizontal pivotal dental engine having certain advan- To enable others interested in the art to which my invention relates to make and use the same, I will now describe its construction and operation, and at the end of this description I will set forth in claims the improvements and features of novelty for which protection by Letters Patent is desired.

In the accompanying drawings, which form part of this specification, and wherein like parts are indicated by like letters and figures of reference in the several views, Figure 1 is a view, in perspective, of a dental chairof an improved pattern having combined with its base a dental engine, the latter being shown in side elevation. 'Fig. 2 is a top plan view of my horizontal pivotal dental engine unfolded. Fig. 3 is a side elevation, partly in section, of the same engine folded for storage or transportation. Fig.4 isa central vertical section through the base of the tool-carrying standard. Fig. 5 is a similar view through the foot of the tool-carrying standard and the post of the base. Fig. 6 is a side view, partly in section, of the upper portion of the toolcarrying standard. Fig. 7 is a side viewof the footof the tool-carrying standarddetached from its support. Fig. 8 is a similar view of the support for said standard, showing the spring which cooperates with the foot. Fig. 9. is a side elevation of the tool carrying standard and its base and co-operating spring and bracket, the latter provided with a stop to limit the rotary movement of the standard; and Fig. 10 is a front elevation of Fig. 9, showing the bracket and spring in section.

Referring to the drawings, A indicates a dental chair of the high-low pattern, the base 7 of which is secured to the floor, as shown.

Around the base 7, through which the spindle S of the chair operates, I fit in a detachable manner a ring or band 9, to which is connectcda bracket 10'. This bracket may be formed integral with one of the hinged sections of bands 9, if desired, and it is so shaped as that when the band 9 is secured in place at the bottom of base 7 it will come quite close to the surface of the foot of said base with its outer horizontal portion 11 very nearly in contact with the fiat surface of plate 12, upon which the foot of base 7 rests.

At the bottom of the horizontal part 11 of bracket 10 there may be fixed a roller 13,

though it is not essential, to facilitate the revolution of the bracket around the chairbase. The frictional contact between the band 9' and base 7 is sufficient to prevent the band from slipping too freely and yet permit it to turn easily in revolving the bracket around the chair. 1

To the horizontal part 11 of bracket 10' I secure the dental engine 00 in any suitable manner. As shown,its frame, which supports the main driving-wheel, is bolted directly to the bracket. This requires said frame to move with the bracket, while the treadle mechanism has a rotary motion independent of the bracket.

It may be desirable to connect the drivingwheel frame to the bracket so that it will have a swinging motion on the bracket. The engine may also be attached to the bracket by a clamp fixed to the engine-frame or to the bracket, by which arrangement the engine may the more readily be removed from its bracket when that is desired; and in order to lock the ring 9firmlytothe base of the chair after having adjusted the engine to the desired position, a clamp may be secured to .said ring to co-operate with the base. Such aclamp will not be found necessary, however, as the weight of the base of the tool-carrying standard of the engine and its pivotal beam will be sufficient to prevent the bracket-ring from revolving when the base of the toolcarrying standard is seated firmly on the floor.

When the engine is not in-use it is foldedunder the foot-board of the chair and occupies a position with reference to the chairbase such as seen in Fig. 1. The engine is also shown in this view in dotted lines, indicating that it has. been swung around to the back of the chair preliminary to its being adjusted for use. In this position the operator is enabled to unfold the treadle mechanism, raise the tool-carrying standard, and

. supply the latter with the required drill or other tool without the patient sitting in the chair observing any of this manipulation. The advantages of thus combining the engine with the dental chair are therefore obvious. Besides the facility with which the engine is manipulated in adjusting it for use without exciting apprehension in the mind of the patient, the tool-carrying standard is quickly and noiselessly moved to any position around the chair.

It is to be understood of course that dental chairs of other constructions than that shown in the drawings may be combined with the engine, and also that the organization of the engine need not be exactly as illustrated. I prefer, however, to employ the engine shown and now about to be described.

My engine comprises a main driving-wheel supported horizontally, a base supporting a tool-carrying standard and connected to a beam of the required length which is pivotally connected to the vertical axis of the main driving-wheel, and a jointed treadle-supporting frame also pivotally connected to the axis of the driving-wheel. This construction provides for the folding of the treadle mechanism quite compactly against the beam connecting the axis of the driving-wheel with the base of the tool-carrying standard, which greatly facilitates the transportation and storage of the engine. The beam D, besides being pivotally connected to the axis of the horizontal driving wheel, is secured to a bracket or arm projecting upwardly fromthe base of the support for the driving-wheel, the point of connection between the bracket and beam being outside of the circumference of said driving-wheel, thus forming an open forked frame, the upper part of which is the pivotal end of the described beam and the lower part the base of the wheel-support. This open forked frame allows of the adjustment of a continuous driving-cord without' removing any part of the engine.

Referring again to the drawings, B indicates the main driving-wheel fixed on the vertical axis or crank-shaft 14, which is maintained in operative position, as shown in Fig. 3, the lower end of said shaft turning in a socket 15, fixed in the lower part of the forked frame 0. The outer or free end of beam D, curved as shown,is provided with a short horizontal bar 18, and is supported by said bar 18 being passed through an opening in the base E of the tool-carrying standard F. The bar 18 is sufficiently long to permit the-base E to be adjusted thereon backward or forward sufficiently to provide for obtaining the proper tension on the driving-cord, which passes around driving-wheel B and over the small guide-wheels 19 at the top of base E and upward to the usual pulley at or near the top of the tool-carrying standard F. Set-screw 20 serves to fix the base E to the bar 18 when the adjustment has been made. The beam D being fixed to frame 0 at 16 moves with it in adjusting the base E and its standard around the operating-chair, and this beam D may be made of any length desired.

The crank of shaft 14 is connected by a suitable link, as 21, and pitman 22, to bell crank lever G, supported on an axis 23 fixed to an upright arm 24, which is formed integral with the pedal-bar H of the pedal mechanism. The bell-crank lever G is connected by link 25 to pedal I by pivot at 26. The pedal I, which is covered with cloth 27, is fulcru med at 28 to a base-bar K, which is pivotally connected to bar H at 29, as shown. The link 25 consists of a short rod with a ball formed on each end. The upper ball is inclosed and turns in a socket at the outer end of the horizontalv arm of the crank G. The lower ball is inclosed and turns in a socket in the toe of the pedal at 26. Thus is formed a double ball-and-socket joint, by means of which the pedal is not only used to operate the bell-crank, but by combination with the pivotal connection of pedal-bar H and base K is given a swinging movement independently of the crank and engine to the .right or left to the extent almost of an entire circle. end to the lower end of the vertical arm of the crank G and at its opposite end to the link 21. The bar H, which sustains the bellcrank lever G, as stated, is pivotally connected to the axis of the main driving-wheel and supported on the frame 0. The vertical flange 30 of bar H servesto strengthen said bar and also to protect the link 22 from the foot of the operator. The arm 31, projecting from bar H near the link 21, receives oneend of a spring or rubber band, the other end of which, secured to a pin 32 in the side of said link, serves in the usual way to throw the The pitman-shaft 22 is connected at one IIO crank over the dead-points to render the movement of the pedal regular. It will be understood of course that the pivotal connection between the bars H and K and the pivotal connection of bar H with the axis of the main driving-wheel and frame supporting the axis of the driving-wheel permit these parts to assume angular positions to each other.

The foot of base E of the tool-carrying standard is provided centrally with a screwthreaded socket to receive the screw-threaded projection 33, by means of which the height of the base may be increased to enable it to rest firmly on the floor whenever necessary. Such adjustment may be required when the Engine is secured to bracket 10, as shown in At the top of post 34 of base E the guidewheels 19 are mounted on short laterally-extending shafts, as shown. The post 34 is hollow at its upper end to receive the support I) for the foot of the tool-carrying standard F. This support I) is grooved, as shown in Fig. 5, which groove receives screw 35, by which arrangement a swivel connection between the standard F and the post 34 is provided. The standard F is thusrendered capable of a horizontal rotary movement in either direction, limited by a stop 36, fixed to the bracket 37, and coming in contact with the part 38 on post 34, as will be understood from Figs. 2, 8,9, and 10. The standard F, which is hinged at its foot to its support b, may therefore be tilted to one side or the other of a line parallel with the beam D when it is desired to have the standard assume such inclinations in the operation of the engine. The bracket 37 is fixed to or formed integral with the support I) for the standard F, and hence moves with it, and its function is to sustain the flat steel spring 39, whose free end extends between ears 40, also integral with the support for the foot of the standard. In Fig. 8 one of these cars is broken away to show the end of the spring. The standard proper, or that part above the support I) for its foot which is adapted to tilt, is constructed at its bottom, as shown in the detached view, Fig. 7, andin section in Fig. 5-tl1at is, with a central lug 41 of the conformation seen in Fig. 7 and curved upper walls 42. The lug 41 is of asize adapting it to fit between the cars 40, its bottom resting against the end of spring 39, as seen in Fig. 5, and its curved walls 42 resting on the curved ends of the cars 40, as shown in the drawings, Fig. 8. The parts are operatively held in this position by pivot 43, as seen in Fig. 5. The standard is prevented from tilting backward by stop avon one of the ears 40, Fig. 8. By this construction when the standard F is tilted forward in a right line, or to the right or left of a right line, the substantially angular end of lug 41 compresses the stiff spring 39, which is secured to bracket 37, and locks the standard in the inclined position to which it has been adjusted,t-hus enabling that direction of the standard to be secured best adapted to the convenience of the operator, and when thus tilted and locked the bracket 37, being fixed to the swiveled support b, and moving with it, the outer end of the standard may be made to describe an arc of a circle limited by stop 36.

The standard F is hollow throughout its length and is fitted with a telescopic section 44, which in turn is also fitted with a similar section 45. Standard F and section 44 are split at their upper ends, as seen in Figs. 6 and 9, and provided with set-screws 46, operating through rings 46, whereby the sections 44 and 45 may be locked when extended. The outer end of section 45 is provided wit-h a socket 47 to receive the nipple of any of the usual attachments carrying the drill and its tube, and a pulley for receiving the driving-cord from the guide-wheels 19.

As the engine is intended to reston the floor when in use, the telescopic standard enables the operatorto place his drill at the exact height desired. WVhen the engine is not in use, or is tobe transported, the tubes or standard F are telescoped and the standard turned down onto and parallel with the beam D, as shown in Fig. 3, and the treadle and its bars II and I are folded against the beam D and frame 0 and locked together by means of hook 48 on .beam D and eye on the side of arm 24 on .bar H.

The feature of hinging the 'standard F at its foot to its supporting-base is an important. part of my organization, as it permits said standard to be-folded down onto the engine structure and its horizontalLy-arranged driving-wheel when the engine is to be stored or transported, and the telescopic character of the standard enables its length to be reduced,

so that when folded down onto the enginestructure, as seen in Fig. 3 of the drawings, it will not extend beyond the horizontal driving-wheel. The folding of the entire apparatus compactly, without dismantling the same, is thus rendered possible.

Having thus described my invention, what I claim as new, and desire to secure by Let-' ters Patent, is-

1. The combination,with a dental chair, of a dental enginepivotally connected to the base of the chair, whereby it may be swung around the chair, substantially as and for the purpose set forth.

2. The combination, with a dental chair, of a dental engine and a bracket upon which -IIO the'engine is mounted, the said bracket .se-

cured to the base of the chair by a pivotal connection, substantially as set forth.

3. The combination, with the base ofa dental chair, of abandor ring encircling said base and carrying a bracket, anda dental engine supported on said bracket, substantially as set forth.

4. The combination, with the base of a dental chair, of a band or ring encircling said base and carrying a bracket provided on its under surface with a roller adapted to travel on the base-plate or floor adjacent to the chair, and

a dental engine secured to said bracket, sub stantially as set forth.

5. The combination, with the base of a dental chair, ofa ban d or ring encircling said base and carrying a bracket provided on its under surface with a roller adapted to travel on the base plate or floor adjacent to the chair, and a dental engine secured to said bracket and havlng a vertically-adjustable base supporting the tool-carrying standard, substantially justable, and set-screw 20, substantially as as set forth.

6. In a dental engine, the combination, with a horizontally-supported main driving-wheel and its frame, of a tool-carrying standard and a supporting-base other than the support for the main-driving-Wheel, the standard hinged to said base and capable of folding down onto the engine structure, substantially as and for the purpose set forth. 1 7. In a dental engine, the combination, with a horizontally-supported main driving-wheel v and its frame, of a telescoping tool-carrying standard and a base for supporting the same,

the said standard hinged to its base, whereby it may be compactly folded down and upon the engine structure, substantially as set forth.

8. In a dental engine, the combination, with a horizontally-supported main driving-Wheel and its frame, of a tool-carrying standard, a base therefor, and a rod or bar connecting the standard to the support for the main drivingwheel, the said standard hinged to itsbase and folding across the horizontal face of the main driving-wheel, substantially as set forth.

9. Ina dental engine, the combination, with a horizontally-supported main driving-wheel, of a pedal and pedalbars pivotally connected to each other and to the axis of said-drivingwheel, a beam and forked open frame also pivotally connected to the axis of the drivi ngwheel, an independent base connected to the outer end of said beam, and a tool-carrying standard hinged to said base and capable of folding onto and parallel with said beam, whereby the entire engine, including the standard, may be compactly folded for storage or transportation, subs antially as set set forth.

11. In a dental engine, the combination, with a horizontal driving-wheel whose axis is supported in frame 0, of horizontal beam D, pivotally connected to said axis and carrying at its outer end the base of the tool-carrying standard, said base divided horizontally and adjustable vertically, substantially as set forth.

12. In a dental engine, the combination, with tool-carrying standard F, swiveled in the post of base E and hinged at its foot, of a bracket supported on said. post to swivel with standard F- and provided with a stop, as 36, and a spring carried by said bracket and cooperating with the foot of the standard, whereby the standard may be tilted from a vertical position and locked, and its outer end made to describe an arc of a circle limited by stop 36 coming in contact with part 38 of said post, substantially as set forth.

13. The combination, with the base E and support I) for the foot of the tool-carrying standard, said support swiveled in said base and having bracket 37 and cars 40, of spring 39, secured to said bracket, and standard F,

having at its foot lug 41, fitting between cars 40 and cooperating with spring 39, substantially as set forth.

Signed at New York, in the county of New I York and State of New York, this 21st day of 

